Receiving device for submarine sound signals



Jan., 13, 1925.

1,523,016 W.HAHNEMANN I HECETVING'DEVICE FOR SUBMARINE SOUND SIGNALSinal Filed Oct'. 28 1915 Patenta& Jan. 131925.

UNITED STATES PATENT "OFFICE,

WALTER EAHNEMAN'N, OF KITZEBERG GERMANY, ASSIGNOR TO SIGNAL`GESELL-SCEAIET MIT BESCERNKTER HAFTUNG, OF KIEL, GERMANY.

REGEIVING DEVICE FOR SUBMARINE SOUND SIGNALS.

Application filed October 28, 1915, Serial No. 58,509. Renewed -Jly 31,1923.

To all whom z'tmay camera:

' Be it known that I, WALTER HAHNEMANN, a subject of the German'Emperor,and residing at Kitzeberg, near Kiel, county of Schleswig-Holstein,State of Prussia, have invented certain new and useful Improvements inReceiving Devices for Submarine Sound Signals, for which I have filed anapplication in Germany, October 26, 1914, of which the following is aspecification.

The invention relates to submarine soundsignal receiving devices inwhich the sound waves arriving in the water are rendered perceptible bymeans of 'an electric, mechanical or optical indicator. It is known thaton the radiation of sound waves in' water the amplitudes of 'force ofthe ex-- cited mass of water -are, on account of the 2 incompressibiltyof the water, great while Accordngly the parts of any receiver whichimpinge directly on the water, for example the outer skin of a ship or amembrane Secured on or in said outer skin, are, since they vibrateaccording to the amplitudes of oscillation of the transmitting medium,excited to very small oscillations. But it has been found from practicalobservations just as from theoreti'cal reflexions, that such smallamplitudes of oscillation are unsuitable and insuficient for Operatingin an economical manner any electrical detector `or a mechanical oroptical indicatur The invention'consists in` introducing between themember that receives the acoustic energy from the' water, for' examplethe outer skin of a ship, and'the member that transforms the receivedacoustic energy into the form of energy to be observed, a system bymeans of which the small amplitudes of oscillation of the molecules ofthe water and of the complying receiving member may be transfer-med intogreat ampli tudes of oscillation before theyreach the indicator.

Systems complying with said requirements are in themselves known inpractice.

They may be adapted 'to the nature of the the amplitudes of oscillationaretvery small.

actual receiving member and of the indicator, and consequently bemanifold in form 5 and arrangenent. In order to' obtain'thetransmissio'n ratio,levers are advantageously used, for example,flexible levers such as springs, the arms of which are so clamped as torepresent level-s of different arm lengths; Sucl a lever as is used inmy construction being, cont'ary to custom, not' jointed to its fulcrumand at its operative ends by a pivotal joint, but'by anchorage, I shallhereafter in .the specfication and claims apply the term jointle sslever to this element of my improved device.

By arranging 'the receiving devices according to the invention theeconomy and the clearness of the receiving devices are in ahigh degreeincreased. A further improvement may still be obtained by tuning thetransmission member or the receiving member to the arriving sound orby'tming and using in concert both of the members.

In the accompanying drawing I have represented by way of example twoembodiments of the invention. Fig; 1 represents a receiving device thetransmitting element of which consists of a jointless lever; rFi 7 5 2is a similar view of a form in whic the transmitting member is shown asa spring-'tongue and Fig. 3 is a modification of the form shown in Fig.`1 in which, however, the spring support H for the lever is omitted. p

In the form shown in 'Fig. 1 A is a diaphragm which is put'tig'htly overan opening of the ships side B. To the interior side in the diaphr'agmA, the one end of a bar or lever C is attached, the free end of whichcarries the armature D of an electromagnetictransmitter E the sound ofwhich is received in the telephone F. A. support G attached to the ships side carries a spring H which 'is Secured to the support by means of ascrew J and influences the bar C' near its bendin point. By means ofsaid spring H which s of secondary consideration for the efl'ect of thereceiver and may be omitted 05 in a given case (see F-g. ,3),the fallingoff -cause the dia'phragn A to'vibrat'e and the vibratons thus areimparted to the bar C. 'The latter acts as a jointless lever of thesecond order, the fulcrum of which is Situated near that end of the barC which v is Secured to the 'diaphragm A., The small amplitudes forcedupon the fixed short arm ot the lever are thus transformed by the freelonger arm 'of theleverinto greater ampltudes of oscillation nearlyproportional to the difference of length of the lever arms.

In the 'form illustra'ted in Fig. 2 the two diaphragms K, K areattached'in parallel 'to the longitudinal sides L, Lj of an 'immersiblecase M' filled with air. Between the diaphragms K, Ka spring-clip N isso Suspended that each of its arms forms a rigid lever of individualthrow. The curved portion O ofthe clip N is reduced in its crosssection, for the purpose of increasin the springiness. Between the freeends o the cli N an indicator, for eX- anple a microp one P, of the sametype or another detector is arrang'ed which is -nnected`to a receiver R.The operation ot' this form is analogous with that of the form shown inFig. 1. l

The` modification Fig'. 3`is substantially .similar to that shown inFig. 1 except that it shows the form of the invention in which thefulcrum support H (F g. 1) for the jointless motion amplifying elementis omitted, being, as has been pointed out at the beginning, notessential for the effective operation in certain cases. In thisparticular modification the location of the fulcrum is determined by therelation of the two masses located at the ends of lever U. In order tobring the fulcrum close to the re- -eiving element so as to causeamplification of the latter s motion at the indicating element, the massat the receiving end of the lever, i. e. at the end fastened to thediaphragm A, should be large, compared with the mass at the other end ofthe lever. This nfi'ect is easily obtained by Virtue'of the t'act thatthe mass of the diaphragm A plus the mass of the sound propagatingmedium (water) directly in contact in it, and which oscillatestherewith, is very large compared with the mass D located at' the otherend ot' lever C. Thus the fulcrum will be located very close to thereceiving end of lever C and a large motion amplitude will result at D-for a comparatively small amplitude of the diaphragm A.

lVhat I claim is:

1. A receiving device for submarine sound signals comprising a receivingdiaphragm directly in contactwith the sound carrying water, an indicatorand a jointlcss lever element, said element being connected between thereceiving diaphragm and the indicator, and' being connected to saidindicator at a point having anamplitude larger thanthat existing at thepoint at which the element is 'connected to said receiving diaphragm. u

'2. A receiving device for submarine sound signals comprising areceiving dia phragm directly in contact with the sound carrying water,an indicator and a jointless lever element, said element being connectedbetween the receiving diaphragm and the indicator, and being connectedto said indicator at a point having an amplitude larger than thatexisting at the point at which the element is connected to saidreceiving diaphragm, said element adapted to positively transmit forcedoscillations, im -,v

parted to it by' said receiving diaphragm in an'plified form to theindicator.

3. A receving devce for submarine sound signals, comprsing a pluralityof remceiving diaphragms each r directly in contact with the soundcarrying water, indicating means and a jointless lever element connectedbetween each of said diaphragms and said indicating means, each of saiddiaphragms being connected to its lever element at a suitable distancefrom the fulcrum` thei-cof, each of said lever elements being connectedto said indicating means at a point further remote from its fulcrum thanthe point at which it is connected to its diaphragm, to cause the smallenergy amplitude received at said diaphragm to be transformed into largemotion amplitudes before they are transmittedto the indicating means.

4. A receiving device for submarine sound signals, comprising aplurality of rev ceiving diaphragms each directly in contact with thesound carrying water, indicating means and a jointless lever elementconnected between each of said diaphragms and said indicating means,each of said diaphragms being connected to its lever element at asuitable distance from the fulcrum therecfl each of said lever elementsbeing connected to said indicating means at a point further remote fromits ulcr'm than the point at which it is connected to its diaphragm, tocause the small energy ampltudes received at said' diaphragms to betransformed into large motion amplitudes and to be positivelytransmitted to the indicating means.

5. A receiving device for submarine sound signals, comprising incombination a sound wave receiving element directly in contact with thesound carryin water, an indicating element, and a sing e jointlessmotion amplifying element interposed between said two first-namedelements andhaving points of relatively small and tively large amplitudeof motion,

'amplfying element being adapted to rectly transmit in amplified formthe motion of the receiving element to the ndicatng element, and sadamplifying element being connected with the receiving element at a pointof relatively small anplitude and with said tively large ampltude. di-In testimony whereo WALTER- Witnesses:

J ULIUS ROYKE, BRUNO KAHLE.

relathe indicating element at a point of rela.-

f I- aflix my signature in presence of two witnesses.

HAHNEMANN

